Screen cylinder drier for fibrous material



y 10, 1952 H. FLEISSNER 3,043,018

SCREEN CYLINDER DRIER FOR FIBROUS MATERIAL Filed June 2, 1958 3 6 34 3735 38 INVENTOR HANS FLEISSNER BY lhglwawd Fawn ATTORNEY Patented July10, 1962 ICC 3,043,018 SCREEN CYLINDER DRIER FOR FIBROUS MATERIAL HansFleissner, Egelsbach-Frankfurt am Main, Germany, assignor to FirmaFleissner & Sohn, G.m.b.l-I. & C0., Frankfurt am Main, Germany, acorporation of Germany Filed June 2, 1958, Ser. No. 739,304 3 Claims.(Cl. 34-115 The invention relates to a screen cylinder drier for fibrousmaterial in which a partial vacuum is produced inside the drum, thusinducing the fibrou material to adhere firmly to the screen drum.

According to the invention a blower is arranged on each side of everyscreen cylinder, preferably in coaxial alignment. This constitutes aconsiderably more economical set-up, because the efiiciency of such ascreen cylinder drier per cubic meter of enclosed space is at a maximum.7

The basic considerations in judging a drying plant are drying time anddrying efliciency. Temperature and an even flow of air per unit time areof importance for the drying process, but there are limits beyond whichtemperature cannot be increased because in some circumstances thematerial that is to be dried would sufler. Consequently, according tothe invention, greater efficiency is achieved-assuming plants of equaldimensions-by stepping up the flow of air.

The fan diameter should be at least 60% of the cylinder diameter.

This increased air-flow must be balanced with the applied heat. In theareas in which suction action is not desired, conventional guard platesare mounted inside the cylinder.

Conveyor mechanisms may be provided between individual screen cylindersor groups of screen cylinders. This permits a greater distance betweenthe individual screen cylinders so that the inspection hatches are moreeasily accessible. The inspection hatches of the cylinders arepreferably in the form of closable slits and should be located at theperiphery of each cylinder.

To each blower heaters should be assigned whose calorific valuescorrespond to the air throughput. To achieve better heat utilization allscreen cylinders may be enclosed in a housing.

The invention is illustrated and explained in more detail in the drawingand the following description.

The drawing shows:

FIG. 1 is a vertical sectional view of a single cylinder drier;

FIG. la is a vertical sectional view taken through the center of P16. 1and viewed toward the right;

FIG. 2 illustrates several groups of single cylinder driers withintervening conveyor mechanisms;

FIG. 3 is an illustration of a multi-cylinder drier subdivided intogroups of two screen cylinders, and

FIG. 4 is an elevational view of an arrangement similar to that shown inFIG. 3, but in which a perforated roller is provided between the firsttwo cylinders in order that the fleece may be conveyed smoothly fromcylinder to cylinder.

FIGURE 1 illustrates the housing 1 of a single cylinder drier with ascreen cylinder 2 at the side of which are two axially located fans 9and 3. The two fans 3 and 9 are of a diameter of at least 60% of thecylinder diameter and exhaust air from the screen cylinder 2, :ausingthe fiber fleece, which is fed in by the apron conveyor 39 and led roundthe periphery of the cylinder, to be held firmly on the periphery. Thefiber fleece is discharged at 40. Due to the strong suction action ofthe two fans 3 and 9, even a. heavy fiber fleece can be led round theentire periphery of the screen cylinder 2 and will adhere well. The areaof the screen cylinder not covered by the fibre fleece is closed ofi bya cover 49, as in all the following possible examples of the invention,by at least one cover plate inside the cylinder at locations where it isdesired to have the, suction discontinued since the fiber fleece is notcarried at such locations. A heater section 50 is arranged adjacent eachfan discharge.

The possible arrangement shown in FIGURE 2 is a multi-cylinder driersub-divided into a number of screen cylinder groups each of which has ahousing 1 in which a screen cylinder 2 is located, which should beprovided with a fan on both sides such as the fans 9' and 3 of FIG. 1but with the fan corresponding to fan 3 of greater capacity than fan 9.The individual groups of screen cylinders are interconnected by aconveyor mechanism for instance an apron conveyor 41. Between theindividual groups of the fiber fleece may also be led over an apronconveyor 42, a drum 43 and a further apron conveyor 44, for instance toloosen up the fiber fleece. Closable openings 45 give access to thescreen cylinders of the individual groups. These openings may be used toget at the drums for cleaning purposes. Covers or baflies 49a arelocated in the interiors of the drums at locations where the fleece isnot to be carried to shut off the suction at such location.

FIGURE 3 shows an arrangement of pairs of screen cylinders 24, 46, eachof which is equipped with suction fans on both sides identical with theFIG. 1 showing, enclosed in a housing 47, the individual groups beingconnected by apron conveyors 25. The openings 26 give access to thescreen cylinders. Cover plates 49b are located where the fleece is notcarried on the drums.

FIGURE 4 shows a further possible arrangement. Here a single overallhousing 27 encloses screen cylinder groups 28, 29, connected by apronconveyors 34 with a screen cylinder group 30, 31; the latter areconnected, in turn, via apron conveyors 35 with a screen cylinder group32 and 33, which likewise has suction fan on both sides as indicated inthe FIG. 1 showing. Access to the openings of the individual screencylinders, which are located at the periphery of the cylinders, isgained through the doors 36 and 37 at the side of the housing. where,for instance, entry can be made below the apron conveyor 34 or 35;access to the screen cylinders is possible from here. Additionalinspection openings 38 are provided at the ends of the housing, throughwhich the operator can gain access to the screen cylinders 28 and 33.Covers 490 are located as indicated to shut ofl suction to the drumperforations.

A special feature of the possible arrangement shown in FIG. 4 consistsin the fact that from the entry point the fiber fleece is led over thetop of the screen cylinders 28 and 29. Being still very moist, the fiberfleece is relatively heavy and, in the case of inherently heavy fiberfleeces in particular, there is a risk that it may fall oil if led overthe underside of cylinder 29. This risk is avoided in the arrangementshown in FIG. 4. A perforated roller is mounted between the two adjacentcylinders 28 and 29. Such a roller 48, as mounted here for example,leads the fleece smoothly from one cylinder to the other (28, 29). Thefiber fleece having been freed of the majority of the moisture afterpassing over the screen cylinder 29, there is no objection to it beingpassed alternately over and under the following screen cylinder groups.1

What I claim is:

l. A drier comprising a plurality of spaced housings, a pair of screencylinders in each of said housings, a blower arrangement for each ofsaid cylinders in said housings for producing a partial vacuum in saidcylinders to hold 3 fibrous material on said cylinders, each said blowerarrangement comprising a pair of coaxially aligned blowers disposed atopposite ends of the respective cylinder, said blower-s being alsoaxially aligned with said respective cylinders and having a fan diameterof at least 60% of the diameter of said respective cylinders, eachblower having an axial inlet toward the associated cylinder and a pairof diametrically opposite discharge outlets to provide a pair of aircirculating paths each including the a respective blower and theperforated wall and the interior of the associated cylinder, aperforated roller disposed between the pair of screen cylinders in atleast one of said housings for transferring the fibrous material betweensuch last named pair of cylinders, each of said cylinders having itsinner surface provided with at least one cover plate to render thesection of said cylinder associated with said cover plate not subject tosuction, and conveyor means extending between said housings fortransferring fibrous material from a cylinder in one housing to'acylinder in an adjacent housing.

2. A drier according to claim 1, wherein said blowers for each cylinderare of different dimensions.

- 4 3. A drier according to claim'l, wherein, in said one housing, thecylinders of the pair rotate in opposite directions and the materialpasses over both cylinders and under said perforated roller; thecylinders of each pair in the other housings rotating in the samedirection and the material passing over one cylinder and under theadjacent cylinder of each pair.

References Cited in the file of this patent UNITED STATES PATENTS347,360 Lorimer Aug. 17, 1886 1,377,793 Schwartz May 10, 1921 1,498,418Ayres et a1 June 17, 1924 2,091,805 Chuse Aug. 31, 1937 2,189,915 Melloret al Feb. 13, 1940 2,755,513 Fleissner July 24, 1956 2,835,047Fleissner et al May 20, 1958 2,950,540 Fleissner Aug. 30, 1960 FOREIGNPATENTS 443,355 Great Britain Feb. 26-, 1936 844,669 Great Britain Aug.17, 1960

